Method for producing thermoplastic articles having thin double walls



July 9, 1968 A. w. THIEL 3,

METHOD FOR PRODUCING THERMOPLASTIC ARTICLES HAVING THIN DOUBLE WALLSFiled May 1966 3 Sheets-Sheet 1 FIG. 20

IN V EN TOR. ALF 0N5 W. TH/EL A T TORNE Y8 July 9, 1968 A. w. THIEL,392,22

METHOD FOR PRODUCING THERMOPLASTIC ARTICLES HAVING THIN DOUBLE WALLSFiled May 5. 1966 .3 Sheets Sheet 2 l S\ g 8 I 8 E 8 m O Q n 211.: r- QS i 2 8 Q In I I JNVENTOR.

I ALFONS Hf. TTH/EL ATTORNEYS July 9, 1968 A. w. THIEL 3.3 2.

METHOD FOR PRODUCING THERMOPLASTIC ARTICLES HAVING THIN DOUBLE WALLS 3Sheets-Sheet 5 Filed May 5, 1966 INVENTOR.

aLrozvs w. TH/EL ATTORNEYS United States Patent 3,392,223 METHOD FORPRODUCING THERMOPLASTIC ARTICLES HAVING THIN DGUBLE WALLS Alfons W.Thiel, Kaiserstrassc 63, Mainz (Rhine), Germany Continuation-impart ofapplication Ser. No. 400,642,

Oct. 1, 1964. This application May 5, 1966, Ser. No. 548,001

18 Claims. (Cl. 264-152) ABSTRACT OF THE DISCLOSURE A method forproducing cup-shaped, double walled thermoplastic articles having aninner wall defined by a liner and an outer wall defined by a cover,wherein a sheet of thermoplastic material for producing the articles isadvanced successively through a forming station and then through ablanking station to shape the liners and covers in successive batches atthe forming station, to blank out each batch of the thusly shaped linersand covers at the blanking station, and to dispense the thuslyblanked-out batch of covers from the blanking station directly onto theliners formed and blanked out in a preceding batch to thereby assembleeach cover in nested relation over an associated liner. The internestedcovers and liners are then transferred to a subsequent station Where theopen end of the liner is beaded around the open end of its associatedcover to form a beaded rim for the finished article.

This is a continuation-in-part of my copending application Ser.No.400,642, filed on Oct. 1, 1964 (now Patent No. 3,283,045 issued Nov.1, 1966) for Process and Apparatus for the Production of Thin-WalledPlastic Articles. Application Ser. No. 400,642 is a divisionalapplication from my copending parent application Ser. No. 51,669 (nowPatent No. 3,161,915), tiled Aug. 24, 1960, which latter application isa continuation-in-part of my parent application Ser. No. 771,864 filedNov. 4, 1958, and issued Dec. 13, 1963, as US. Patent No. 3,115,677.

This invention is concerned with a method for producing articles fromthermoplastic material, such articles having an inner lining wall and anouter wall which are held together on the opening edge through the useof a beaded rim.

The known manner of producing such double-walled plastic articles hasbeen, until now, difficult and expensive. This has been due to the factthat the liner and outer part has first to be produced separately, mostoften by a vacuum deep drawing process from thermoplastic sheetmaterial, blanked out from the surrounding material, and, in a separateoperation, assembled together. These pairs of liner and outer partsbeing assembled had then to be fed very carefully into the beadingapparatus in order to prevent possible shifting, especially in the edgeregion of the liner with respect to the outer cover during feeding intothe beading apparatus or during the beading operation.

It therefore is the object of this invention to provide an improved andnovel method by which the joining of liner and outer parts can proceedvery much faster, more simply, and more effectively than before, and bywhich the feeding of the assembled pairs of liner and outer parts intothe beading apparatus need not require the extreme care atend-ant withprior methods. In this way, the production of double-walled articlesaccording to the present invention, is faster, simpler, and cheaper ascompared with production by conventional methods.

The foregoing objects essentially are accomplished by joining the newlyformed outer part or cover with the "Ice liner immediately after thecover is blanked out of the track or sheet of material. The liner isproduced beforehand and placed ready for reception of the outer part. lnthis way, the cold, or at least already greatly cooled, and thus morestable liner grips the still relatively warm, newly blanked outer partor cover. Immediately after the blanking of the outer part, the twojoined pieces can be beaded on the open edge to provide a finalfastening. The still warm, newly blanked outer part immediately shrinksslightly on the cold or at least cooler liner so that a certain amountof gripping has already been obtained 'before the beading operation.Consequently, even at high operational speeds, each pair of pieces (theouter cover and liner) can be fed without exercising great care to thebeading apparatus and beaded without danger that one of the pieces willshift relative to the other.

In one embodiment of the invention, the liners and outer coversinitially are shaped in batches from plastic material in a continuousdeep-draw process and then are immediately blanked or cut out from thetrack or sheet of plastic material. This initial step yields batches offormed pieces made up half of outer covers and half of liners. Afterbeing blanked out, the outer covers are placed on a previously producedbatch of liners, while the liners from the instant batch are made readyfor reception in the outer covers from the next batch. This embodimentof the invention makes it possible to carry out the method very quickly,simply and cheaply.

Failure-free performance of the method] of this invention can still beimproved significantly by wedging or locking the liner and the outercover of the article together during the joining operation and beforeheading of the edge when the edge of the outer cover is securely seatedin the collar of the liner. To accomplish this, the outer cover and theliner are provided with parts which coact to effectively lock the linerand cover together by applying axial pressure during the joiningoperation.

It is also an object of the invention to provide a novel apparatus forcarrying out the method of the preceding object. This apparatuscomprises at least one forming machine for the batch production ofplastic articles in a track or sheet of material and, in each case, afollowing blanking machine for blanking or cutting out the formedarticles into batches of equal numbers.

The blanking machine has openings in its die table. The blanked outarticles fall through these openings onto a transport device which feedsthem to the beading machine. According to this invention, the openingsin the die table in such a machine are disposed of in such a way thatone batch of blanked out liners are set on a conveyor device and aremoved thereby with. step-wise motion to positions Where they arevertically under the blanking opening through which the covers aredispensed. In this Way, the newly blanked-out, war-m covers are fedimmediately and directly onto the waiting, already cold or at least moregreatly cooled liners. Only a single forming machine need be used in theapparatus of this invention when the forming machine is constructed,with respect to the direction of the track of material, to shape coversin the forward half and liners in the rearward half. Similarly, only oneblanking machine is required by constructing it to cut out the shapedcovers in a forward section and to simultaneously cut out the shapedliners in its rearward half.

Furtherobjects of this invention will appear as the description proceedsin connection with the appended claims and annexed drawings wherein:

FIGURE 1 is an elevation of a plastic double walled cup constructedaccording to the principles of this invention;

FIGURE 2a is a fragmentary vertical section of the cup shown in FIGURE 1and illustrating the head around the rim thereof in partially finishedform;

FIGURE 2b is a fragmentary horizontal section taken through the middleside wall region of the cup shown in FIGURES 1 and 2a;

FIGURE 2:: is a fragmentary view similar to FIGURE 2a, but showing thehead around the mouth of the cup in finished form;

FIGURE 2d is a fragmentary perspective view of the outer cup shown inthe previous figures;

FIGURE 3a is a vertical section similar to FIGURE 2a and illustrating afinished cup of somewhat different form;

FIGURE 3b is a fragmentary horizontal section of the cup shown in FIGURE3a and taken through the cup side about midway between the top andbottom thereof;

FIGURES 4a and 4b together diagrammatically show a novel apparatus forcarrying the method of this invention; and

FIGURE 5 is a fragmentary section showing a modification of the doublewalled cup of this invention.

The embodiments illustrated in the drawings are for a double-walled cupformed from thin-walled plastic material and intended especially for hotdrinks. The doublewalled cup comprises an outer cup 1 and a lining cup2. FIGURES 1 and 2a show one construction in which the gap between theside walls of outer cup 1 and lining cup 2 is fixed by double-walledribs 3. Ribs 3, which are integral with cup 1, extend inwardly from theouter side wall periphery of cup 1 and are sufliciently narrow that theexternal side wall surface of cup 1 has the appearance of beingessentially round. These ribs 3 seat against the outer surface of cup 2along a very narrow, practically line-shaped interface. As shown, ribs 3extend between the bottom of cup 1 and a smoothly contoured, beaded rim4 delimiting the mouth of the cup. Lining cup 2 can be formed with asmooth interior contour, such practice being advantageous for completeemptying of the drink during drinking.

As shown in FIGURE 2a, rim 4 comprises an outwardly projecting, curled,skirt portion of approximately semi-circular cross-section. The liningcup 2 is formed with a rounded rim section 5 at its outer end and amatching, ring-shaped collar 6. Collar 6 comprises an outwardly flared,marginal skirt which is integrally joined to the body of cup 2 by rimsection 5. Section 5 and rim 4 advantageously are so formed, that theylie in contact throughout their entire opposed surfaces when lining cup2 is loosely inserted into outer cup 1.

lif it is desired to produce a continuous elastic tension in rim 4during the beading operation, the rounded part of rim 4 is provided witha slightly larger radius of curvature than that given the section 5 onthe edge of lining cup 2. Pressing of lining cup 2 into the outer cup 1then immediately gives rise to the elastic tension in rim 4. In order tosecurely hold lining cup 2 in its pressedin, internested position,depression 7b (see FIGURE 2d) are formed in the inner edges of ribs 3 toeffectively define an inwardly opening, annular groove 7. Depressions 7bare disposed a short distance above the bottom of cup 1 and provides anannular shoulder 7a facing the cup bottom. Depressions 7b are suitablyformed by notching or pressing portions of ribs 3 outwardly. A matingring or annular lip 8 integrally formed on lining cup 2 snaps into andinterfittingly seats in groove 7 to interlock behind shoulders 7a whencup 2 is pressed into cup 1. Cup 2 is thus securely held in itspressed-in position by seating engagement of ring 8 in groove 7. Ring 8,as shown, radially protrudes from the side wall periphery of cup 2.

FIGURE 20 shows the rims of cups 1 and 2 in finished form. In thisfigure, collar 6 is headed into a lip roll 9 of hollow, ring like,rounded contour. Rim 4 is beaded into lip roll 9 as a result 'of headingcollar 6. Rim 4 is thus held under continuous elastic tension.

In the embodiment of FIGURES 3a and 3b, ribs 3, which retain the sidewall portion 11 of cup 1 spaced outwardly from the opposing side wallperiphery of cup 2, extends only along a limited length of the cup, thislength being essentially confined to the region in which thedouble-walled cup is normally held in a persons hand.

In place of the locking ring and groove construction, the embodimentshown in FIGURES 3a and 3b provides for a wedged engagement of cup 2 incup 1. This is accomplished by forming cup 2 with an annular ribbedregion 12 extending around the side wall periphery of the cup near thebottom thereof. Ribber region 12 is formed by a series ofcircumferentially spaced apart, accuratelybottomed grooves or recesseswhich define outwardly and vertically or longitudinally extending ribs13. The manner of wedging can be seen in FIGURE 3b.

Ribs 13 in region 12 are formed in such a way that they protrude, whenundeformed, slightly outwardly beyond a conical envelope containing theouter periphery of lining cup 2. The opposing interior wall surface ofcup near the bottom thereof. Ribbed region 12 is formed When lining cup2 is shoved into outer cup 1, the outwardly projecting ends of ribs 13come in contact with the inner surface of outer cup 1 and are pressed ordeformed slightly inwardly when lining cup 2 and outer cup 1 are tightlypressed together. This can be seen at 14 in FIGURE 31). In this way,lining cup 2 clings tightly to outer cup 1, even when lip roll 9' hasnot yet been formed. The annular interior region of cup 1 which isengaged by ribs 13 is below ribs 13 and somewhat above the bottom wallof cup 1.

After cups 1 and 2 are interlocked in assembled relationship, the cupassembly can be handled quite readily and easily. In particular, atransportation or conveyor device, to be described later on, can be usedin which the bottom of outer cup 1 is sucked onto the lower side of aplate. Such a device is especially suited for placing the pairs of linerand outer cup parts into the beading machine. In the beading machine,the collar 6 is beaded around rim 4 of cup 1 and, in this way, rim 4 maybe elastically deformed. In the final stamping and forming of lip roll9, it is stabilized and thus a release of the stressed state in rim 4 ata later time is prevented.

Referring back to FIGURE 2a the bottom of cup 1 is curved concavelyinwardly in its central region 22. Region 22 is peripherally surroundedby an annular, substantially flat bottom rim 21 which joins region 22 tothe side wall of the cup. Cup 2 also has the central region 23 of itsbottom curved concavely inwardly so that the concave cup bottom regions22 and 23 matingly come in contact with each other when cup 2 isinserted into cup 1 and ring 8 locks in groove 7. The bottom regions 22and 23 can, if desired, be slightly deformed elastically, so that anoutward resilient biasing effect is exerted on cup 2 to urge ring 8forwardly into interlocking engagement with shoulder 7a. Thus, theassembly of cups 1 and 2 already have a secure, tight hold even beforethe final fastening is made by the beading of the cup rims.

As shown in FIGURE 2a, ring 8 provides a downwardly facing annularshoulder 24 which seats against an opposing shoulder on cup 1 when cup 2is nested therein.

In the embodiment of FIGURES 3a and 3b, the bottom of cup 2 is shown tobe spaced above the bottom of cup 1.

The continuous production of double-walled cups according to the methodof this invention is accomplished, for example, by the apparatus shownin FIGURES 4a and 4B. In this apparatus, a track or sheet 101 ofthermoplastic material is advanced first with step-wise movement by asuitable conveyor device 109 through a heating zone 108. Sheet 101 isheated in zone 108 sufficiently for the subsequent forming. For example,sheet 101 is heated for a length of time such that it begins to hang orsag like a sack. The length of this heating zone 108 is equally as largeas the stepmovement imparted to sheet 101 by conveyor device 109 and theeffective working lengths of a forming machine 102 and a blankingmachine 202. Conveyor device 109 may be of any conventional form havinga belt or the like trained around motor driven rollers.

Forming machine 102 comprises a vacuum deep drawing apparatus having afemale tool 102a mounted below a vacuum chamber 105. On the bottom sideof tool 102a a swingable frame 110 is mounted for assuring an air tightseal. Forming machine 102 is generally the same as that described in theaforesaid copending application Ser. No. 400,642 to which reference ismade for further detail. If needed, stretchers may be employed asdescribed in application Ser. N0. 400,642. Forming machine 102, alongwith its carriage and vacuum chamber 105, is movable up and down in avertical direction and contains a number, for example 48 and more, offorming spaces. Of these, only four are shown in the drawing. Therearward half of forming tool, in the direction of sheet movement, isprovided with article forming cavities 103 that are configured forproducing lining cups 2. The forward half of tool 1020, with respect tothe direction of sheet movement, has forming cavities 103a configuredfor the production of the outer cup 1. Forming cavities 103 and 103a arematched in number and arrangement and are connected to chamber 105 bypassages 105a. Between the two groups of forming cavities 103 and 103a,there is a leg section 103b. Its width corresponds to the width of thepiece that is formed between each batch of cups 1 and 2 for stiffeningsheet 101. The section of sheet 101 heated in zone 108 is advanced in asingle step-wise movement to a position where it is directly under tool102a and seats against the outer edges of cavities 103 and 103a. Byevacuating chamber 105, therefore, the portions of sheet 101 aligningwith cavities 103 and 103a are sucked up into the cavities to therebyshape cups 1 and 2. Reference is made to the aforesaid applicationSerial No. 400,642 for further detail concerning this cup shapingoperation.

The reference character 201 designates that portion of sheet 101containing the formed, but uncut cups 1 and 2. Sheet portion 201 is fedinto blanking machine 202, which also is essentially the same as the onedescribed in application Ser. No. 400,642. Blanking machine 202, asshown in FIGURE 4b, comprises a receptacle 210 having blanking cutters210a disposed vertically above a die table 220. Die table 220 hasopening 221a and 221b, The lining cup and outer cup forms in sheetportion 201, are inverted and cut out by displacing cutters 210adownwardly. The cut-out cups 1 and 2 are dispensed from machine 202 byfeeding them downwardly through openings 221a and 221b respectively.

A conveyor device 301 similar to device 109 has a belt or otherhorizontally extending support surface disposed vertically belowopenings 221a and 221k. The cut-out cups 1 and 2 thus drop in invertedpositions onto the horizontal support surface of device 301. The lengthof step-wise advancement imparted to this horizontal conveyor supportsurface is equal to one-half the length of step-wise advancementimparted to sheet 101 by device 109. The step-wise movements applied bydevices 109 and 301 are suitably synchronized with each other and withthe operation of machines 102 and 202. The blanket-out forms of liningcups 3 are therefore first fed downwardly through openings 221a ontodevice 301 and are advanced in one step-wise movement to positions wherethey are vertically under and aligned with openings 221b so that theblanked-out outer cups 1 fall through their openings 221b directly ontothe punched or cut outlining cups 2 sitting on device 301. FIGURE 2ashows the'configuration of rim 4, rim section 5 and collar 6 uponremoval of the cup pairs from machine 202.

From the foregoing description it is clear that the outer cups 1 of-eachbatch dispensed from machine 202 is assembled on cup 2 formed in thepreceding batch. Cups 2, being in the preceding batch, will be muchcooler than cups 1 in the succeeding batch. Upon cooling, therefore,cups 1 shrink relative to cups 2 and thus more firmly grip cups 2 as theassemblies of internested inner and outer cups are advanced by conveyordevice 301 to a device 501 for pressing and locking or wedging the cuppairs together.

Device 501 comprises a plurality of fingers 502 and pestles 503 fixed onthe upper ends of fingers 502 and corresponding to the number ofarticles in each batch conveyed through the machine. Fingers 502 withtheir pestles 503 are pushed upwardly after every second stepwisemovement of device 301. Their upward movement is accomplished by anysuitable means such as, for example, an unshown pneumatic or hydrauliccylinder and piston arrangement. Pestles 503 are shifted through theconveyor support surface of device 301 until the pestles seat againstthe bottom 'of lining cup 2. The cut-out pairs of cups 1 and 2 arepressed by pestles 503 against a porous plate 504. This pressure issufficient to first of all lock the lining and outer cups byinterengagement of ring 8 and groove 9 when cups 1 and 2 are constructedaccording to the embodiment of FIGURE 2. Where cups 1 and 2 areconstructed according to the embodiment of FIGURE 3, the pressureexerted by fingers 502 and pestles 5'03 wedge the ribbed region 12 intothe smooth peripheral interior of cup 1 between ribs 3 and the bottom ofthe cup.

Still referring to FIGURE 4b, a casing mounted on plate 504 provides asuction chamber 506 which is delimited by the upwardly facing surface ofplate 504. A line 505 is connected to provide a vacuum in chamber 506above the porous plate 504 so that the cup pairs are held tightly ininverted positions against the bottom surface of plate 504 by suctionwhen fingers 502 are drawn away. As soon as fingers 502 with theirpestles 503 are withdrawn into their downwardly displaced positions,plate 504- is shifted in the direction of the arrow to a position whereit is over a plate 402. There, the vacuum in the chamber 506 is releasedor replaced by a slight positive pressure so that the cup pairs arereleased onto supports 323 mounted on plate 402. Guiding fingers 404-may be associated with the supports 323 and are actuated by hydraulic orpneumatic cylinder and piston assemblies 407. As soon as the cup pairsare placed on supports 323, a multiple beading tool 423, which ismovable upwardly and downwardly in the direction of the arrow 242a, islowered. The construction and the operation of this multiple beadingtool are the same in all sections and is generally the same as thatdescribed in the aforesaid copending application Ser. No. 400,642. Thefinal configuration of the bead produced by tool 423 is shown in FIGURES2c and 3a.

The removal of the finished, beaded, double-walled cups from supports323 can be accomplished in any suitable manner, one example being therepeated use of a porous plate connected with a vacuum chamber.

In the embodiment of FIGURES 2a-2d, the formation of depressions 7b doesnot change the contour of the outer periphery of cup 1 since ribs 3extend radially inwardly. If the appearance of an annular ring on theexterior of cup 1 is not objectionable, however, cup 1 may beconstructed in the manner shown in FIGURE 5. In this embodiment, ribs 3terminate a short distance above the cup bottom, and cup 1 is providedwith a smooth, annular side wall 25 extending between the lower ends ofribs 3 and rim 21. An annular groove 26 is formed in wall 25 by pressinga portion thereof radially outwardly. Lip 8 snaps into andinterfittingly seats in groove 26 to interlock cups 1 and 2 ininternested relation in the same manner as described in the embodimentof FIG- URES 2a-2d. An annular shoulder 27 formed in cup 2 seats againstan opposed surface on cup 1 when cup 2 is nested in the outer cup.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. In a method for producing cup-shaped double-walled thermoplasticarticles wherein the inner wall is defined by a liner and the outer wallby a cover and wherein both walls are joined at the opening end in abeaded rim, said method comprising the steps of providing separateforming and blanking stations, advancing a sheet of thermoplasticmaterial successively through said stations, shaping said liners andcovers in Successive batches in said sheet at said forming station,blanking out each batch of thusly shaped liners and covers from saidsheet at said blanking station, dispensing the thusly blanked-out batchof covers from said blanking station directly onto liners formed andblanked out in a preceding batch to assemble each cover in nestedrelation over an associated liner for providing the inner and outerwalls of said article, and thereafter beading the open end of each lineraround the open end of its associated cover to form said beaded rim.

2. The method defined in claim 1 comprising the steps of heating saidsheet to effect the shaping of said liners and covers at said shapingstation, advancing the shaped liners and covers to be blanked out atsaid blanking station while still warm, allowing the liners in saidpreceding batch to cool relative to the covers in which they arereceived, and allowing said covers to cool on said liners to therebyshrink and grip said liners.

3. The method defined in claim 1 wherein during beading of the open endof each liner, the open end of each liner is curied back toward saidouter wall and into a ring-like roll around the open end of said coverto form said rim and to fasten said liner to its associated cover.

4. The method defined in claim 1 wherein the liners and covers of eachbatch are simultaneously shaped and blanked out at said forming andblanking stations respectively.

5. The method defined in claim 4 wherein the liners of said precedingbatch are dispensed from said blanking station and advanced in invertedpositions to locations vertically below respective covers in thesucceeding batch, and wherein said covers are dispensed from saidblanking station in inverted position to drop onto the inverted linersin said preceding batch.

6. The method defined in claim 5 wherein said covers loosely seat on theliners of said preceding batch upon being dispensed from said blankingstations, and wherein prior to beading of the outer end of each linerbut after said covers are loosely seated on said liners, said methodfurther comprises the step of securing each liner in its respectivecover by applying pressure to axially advance each liner further intoits respective cover. I

7. In a method for producing double-walled, thermoplastic article'swherein the inner wall is defined by a liner and the outer wall by acover and wherein both walls are formed at an open end in a beaded rim,the steps comprising separately forming said liner and said cover,imparting relative motion to said cover and liner to assemble said linerin said cover, interlocking said liner and said cover and therebyprovide said inner and outer walls of each finished article to preventoutward displacement of said liner, and thereafter beading the open endof said liner around the open end of said cover to provide the assemblyof said cover and inserted liner with a beaded rim around the mouththereof.

8. The method defined in claim 7 wherein said liner and cover areinterlocked by applying axially opposed pressures to wedge said liner insaid cover.

9. The method defined in claim 7 wherein said liner and cover areinterlocked by providing abutment surfaces on said cover and said linerand by relatively advancing said liner into said cover to move the linerabutment surface beyond the cover abutment surface and to seat againstsaid cover abutment surface.

10. The method defined in claim 7 wherein during beading of said liner,the open end of said liner is curled back toward said outer wall andinto a ring-like roll around the open end of said cover to form said rimwith a rounded contour and to fasten said cover and said liner together.

11. The method defined in claim 7 wherein successive batches of theliners and covers are simultaneously shaped and then simultaneously cutout from the same sheet of material.

12. The method defined in claim 11 wherein the covers of one batch areplaced on the liners of the preceding batch.

13. The method defined in claim 12 wherein said covers of said one batchare first loosely placed on the liners of said preceding batch andwherein the inserted liners are then interlocked to their associatedcovers by relatively advancing them a further predetermined distanceinto their associated covers.

14. The method defined in claim 13 wherein said liners are interlockedwith their associated covers at one station and then advanced ininverted positions with the mouths of said liners facing downwardly to asecond station where said beaded rims are formed thereon.

15. A method for producing cup-shaped double-walled thermoplasticarticles wherein the inner wall of each article is defined by a linercup, wherein the outer wall of each article is defined by an outer cup,and wherein both the inner and outer walls of each article are joined atthe opening end in a beaded rim, said method comprising the steps ofproviding separate shaping and blanking stations, advancing a sheet ofthermoplastic material successively through said stations, at saidshaping station forming in successive batches the liner cups each withan outwardly extending collar comprising an outwardly flared marginalskirt and the outer cups each with an outwardly extending rim portionsurrounding the outer cup opening, blanking out each batch of thuslyshaped liner cups and outer cups from said sheet at said blankingstation, and dispensing said thusly blanked-out batch of outer cups fromsaid blanking station directly onto said liner cups shaped and blankedout in a preceding batch to form pairs each containing of a liner cupand an outer cup, axially pressing together the liner cup and outer cupof each of said pairs to engage the said outwardly extending rim portionof the outer cup against said outwardly extending collar of said linercup, and curling said outwardly extending collar of said liner cup intoa ringlike roll of rounded contour around said outwardly extending rimportion of said outer cup to form said beaded mm.

16. The method defined in claim 15 comprising the steps of forming atsaid shaping station cooperating locking formations on the liner andouter cups of each of said pairs, loosely nesting the outer cups overtheir associated liner cups as they are dispensed from said blankingstation, and thereafter inter-engaging said formations of said liner andouter cups of each pair are axially pressed together to interlock theliner and outer cups of each pair before said collar is curled aroundsaid rim portion to form said beaded rim.

17. A method for producing double-walled, thermoplastic articles whereinthe inner wall is defined by a liner cup and the outer vall by an outercup and wherein both walls are formed at an open end in a beaded rim,the steps comprising separately shaping the liner cups to have anoutwardly extending collar comprising an outwardly fiared marginalskirt, shaping the outer cups to have an outwardly extending rim portionsurrounding the outer cup opening, imparting relative motion to saidouter cups and liner cups to nest one liner cup into one outer cup andto engage said outwardly extending rim portion of said outer cup withsaid outwardly extending collar of its associated liner cup, andthereafter curling said outwardly extending collar of said liner cupinto a ring-like roll of rounded contour around said outwardly extendingrim portion of the associated outer cup to form said beaded run.

18. A method for producing double-walled, thermoplastic articles whereinthe inner wall is defined by a liner cup and the outer wall is definedby an outer cup and wherein both walls are formed and fastened togetherat the open end of said article in a beaded rim, the steps comprisingshaping the liner cups and the outer cups in succesive batches with theouter cups being shaped in a forward portion of each batch, with theliner cups being shaped in a rearward portion of each batch and beingequal in number to the outer cups shaped in said forward portion of eachbatch, and with all of the cups in each batch being simultaneouslyshaped, forming each liner cup as it is shaped with an outwardly flaringcollar comprising an outwardly flared marginal skirt at the open end ofthe cup, forming each outer cup as it is shaped with an outwardlyextending rim portion surrounding the outer cup opening, blanking outthe liner cups and outer cups in each batch after shaping, moving theblanked outer liner cups of one batch vertically below the region wherethe outer cups of a succeeding batch are blanked out, thereafterimparting relative vertical motion to the liner cups from said one batchand to the outer cups from said succeeding batch to nest each outer cupover one of the inner cups to assemble the liner and outer cups in pairsand to engage said outwardly extending rim portion of each outer cupwith the outwardly extending collar of its associated liner cup, andthereafter curling the outwardly extending collar of each liner cup intoa ring-like roll of rounded contour around the outwardly extending rimportion of the associated outer cup to form said beaded rim.

References Cited UNITED STATES PATENTS 2,090,528 8/1937 Ferngren 2641632,859,575 11/ 1 958 Lehmann 264296 2,953,814 9/1960 Mumford 2641633,052,926 9/1962 Quinche 1859 3,115,677 12/1963 Thiel 26492 3,120,570 2/1964 Kennedy 264269 3,207,830 9/1965 Aldington 264249 3,244,780 4/1966Levey 264--294 3,247,302 4/1966 Lewis 264263 ROBERT F. WHITE, PrimaryExaminer.

R. R. KUCIA, Assistant Examiner.

